1. Technical Field
The present invention relates to an image formation device and an image formation method.
2. Related Art
In an inkjet-recording-type image formation device, there is the problem that, when ink is ejected continuously, poor ejection of ink occurs. This is particularly marked in cases in which a large amount of ink is ejected from the nozzles. In such cases, it is possible to restore good ejection quality by providing an appropriate stoppage time. However, if printing is stopped too frequently, the total printing speed (throughput) when printing the needed number of sheets decreases, and the burden on the user increases.
The following two factors are considered as main causes of a decrease in throughput due to the provision of stoppage time. (1) In the first place, printing is not carried out during the stoppage time. (2) Immediately after the stoppage time ends and there is a return to printing, preparation time is needed, and printing cannot be carried out during this preparation time.
In the case of inkjet-recording-type image formation devices for so-called “home use” that are conventionally used, the image formation device is compact, the operation of the conveying system is simple, and a heating/drying section is not provided. Therefore, aforementioned factor (2) substantially hardly ever arises.
On other hand, in recent years, the application of inkjet image formation devices for use as commercial printers (digital printers) or as printers for office use has expanded. It is often the case that image formation devices that are used in such applications are large, and are provided with a heating/drying section and a fixing section. Therefore, aforementioned factor (2) becomes problematic.
As a technique of providing a stoppage time during the printing operation, there is the technique disclosed in Japanese Patent Application Laid-Open (JP-A) No. 2009-66796.
JP-A No. 2009-66796 discloses a technique in which sheets, on which ink or toner has been printed but is still in an unfixed (undried) state, are stacked in a sheet discharging section, and, in order to prevent the ink or toner from dirtying other printed matter, a predetermined stoppage time is provided, on the basis of the amount of ink that is used during printing, from the end of the printing processing of this time (the Nth sheet) until the start of the printing processing of the next time (the (N+1)st sheet).
However, the technique disclosed in JP-A No. 2009-66796 is a technique whose object is the prevention of soiling by undried ink after printing, and therefore, the printing operation is stopped during the stoppage time. Thus, even if this technique is applied as a means for solving the problem of poor ejection due to continuous printing, the printing operation is stopped during the stoppage time. Therefore, above-described factor (2) remains as it did before, and the object of suppressing a decrease in throughput cannot be achieved.